plotRGB: Red-Green-Blue plot of a multi-layered Raster object

In raster: Geographic Data Analysis and Modeling

Red-Green-Blue plot of a multi-layered Raster object

Description

Make a Red-Green-Blue plot based on three layers (in a RasterBrick or RasterStack). Three layers (sometimes referred to as "bands" because they may represent different bandwidths in the electromagnetic spectrum) are combined such that they represent the red, green and blue channel. This function can be used to make 'true (or false) color images' from Landsat and other multi-band satellite images.

Usage

## S4 method for signature 'RasterStackBrick'
plotRGB(x, r=1, g=2, b=3, scale, maxpixels=500000, stretch=NULL, 
ext=NULL, interpolate=FALSE, colNA='white', alpha, bgalpha, addfun=NULL, zlim=NULL, 
zlimcol=NULL, axes=FALSE, xlab='', ylab='', asp=NULL, add=FALSE, margins=FALSE, ...)

Arguments

x	RasterBrick or RasterStack
r	integer. Index of the Red channel, between 1 and nlayers(x)
g	integer. Index of the Green channel, between 1 and nlayers(x)
b	integer. Index of the Blue channel, between 1 and nlayers(x)
scale	integer. Maximum (possible) value in the three channels. Defaults to 255 or to the maximum value of x if that is known and larger than 255
maxpixels	integer > 0. Maximum number of pixels to use
stretch	character. Option to stretch the values to increase the contrast of the image: "lin" or "hist"
ext	An Extent object to zoom in to a region of interest (see drawExtent)
interpolate	logical. If TRUE, interpolate the image when drawing
colNA	color for the background (NA values)
alpha	transparency. Integer between 0 (transparent) and 255 (opaque)
bgalpha	Background transparency. Integer between 0 (transparent) and 255 (opaque)
addfun	Function to add additional items such as points or polygons to the plot (map). See plot
zlim	numeric vector of length 2. Range of values to plot (optional)
zlimcol	If NULL the values outside the range of zlim get the color of the extremes of the range. If zlimcol has any other value, the values outside the zlim range get the color of NA values (see colNA)
axes	logical. If TRUE axes are drawn (and arguments such as main="title" will be honored)
xlab	character. Label of x-axis
ylab	character. Label of y-axis
asp	numeric. Aspect (ratio of x and y. If NULL, and appropriate value is computed to match data for the longitude/latitude coordinate reference system, and 1 for planar coordinate reference systems
add	logical. If TRUE add values to current plot
margins	logical. If TRUE standard whitespace margins are used. If FALSE, graphics::par(plt=c(0,1,0,1)) is used
...	graphical parameters as in plot or rasterImage

Author(s)

Robert J. Hijmans; stretch option based on functions by Josh Gray

See Also

plot

Examples

b <- brick(system.file("external/rlogo.grd", package="raster"))
plotRGB(b)
plotRGB(b, 3, 2, 1)
plotRGB(b, 3, 2, 1, stretch='hist')

raster documentation built on Oct. 3, 2024, 1:08 a.m.